Press for cutting sheet metal



May 17, 1949. c. -MRI-lomas PRESS FOR CUTTING SHEET METAL 2 shets-sheet 1 Filed Jan. 1'?,v 1947 1NVENTOR.

:moana/s May 17, 1949 c. J. RHODES 2,470,110

PRESS FOR CUTTING SHEET METAL Filed Jan. 17, 1947 2 Sheets-Shea?l 2 l/ /z 1/ i@ 7 f Fles. `O

el @l '5" 7 i 5/ 1 I Q /s l3- j yMl ,QS l@ /8 'E :NVE mon I7 0 MSWJZAOJ Mm A Patented May 17, 1949 UNITED PRESS FOR CUTTING SHEET METAL Charles Joseph Rhodes, Wakeeld, England Application January 17, 1947, Serial No. 722,653 In Great Britain November 6, 1946 Claims.

This inventi-on relates to presses for cutting sheet metal Iand particularly to presses of the lopen cap or over-hanging type. In presses of this type, due to the overhang, the C-shaped frame is liable to spring or deflect to yan appreciable extent under full load or pressure and to compensate for this deection it is customary to so Vconstruct such presses that the surface of the work table and the face of the ram are slightly out of parallel, so that under full load or pressure `the two faces lie in parallel planes. This expedient, however, has a deleterious effect on the cutting edges of the dies causing them to wear rapidly.

In `order to neutralise the adverse effects of the deflection of the C-shaped frame, in a press yof the above type it has previously 'been proposed to arrange the ram to slide on a :pair of vertical rods, supported `by the lower part of the press frame at points below the work table and extending above the work table, said rods also carrying brackets with bosses at one end through which said rods pass and bosses at their other end through which slide another pair lof Vertical rods supported at their ends by the cam in lparallel relationship to the rst-mentioned pair of vertical rods.

According to this invention the ram is guided for reciprocation by grooves of part-circular cross-section formed therein sliding Ion part-cylindrical members rigidly secured to a bracket carried on upright pillars, which pillars are supported by the lower vpart Iof fthe lpress frame at points below the work table and extending above the work table.

The part-cylindrical slides are extremely accurate and require a minimum of setting. Moreover Ithe new arrangement enables -a much lighter ram of cheaper construction to be employed.

Preferably the bracket is adjustably mounted on the upright pillars, so that it may 'be adjust- -ed upwards or downwards to conform with adjustments made in the stroke of the ram. If, for example, the ram were so adjusted to accommodate certain dies that it projected too far below the slides at the bottom of the stroke, a certain loss of rigidity and accuracy would take place, but this loss may :be obviated by a corresponding downward adjustment of the bracket.

The ram is operated from a crank pin by means of a coupling.

One embodiment of the invention will now be described and illustrated with reference to the accompanying drawings, in which:

Fig. 1 is a diagrammatic side elevation,

Fig. 2 is a detail front elevation, and

Fig. 3 is `a cross section on the line 3--3 of Fig. 2.

Referring to the drawings which only illustrate the parts of a press of the open gap or overhanging type that are necessary for the understandingr of the invention, the reference numeral I indicates the gapped fand substantially C-shaped frame, the upper part of which over'- hangs the lower part 2, having depending wings 3 and supporting the work table 4.

Bolts '24 and 25 are provided for securing the frame to a base.

The lower parts Iof two vertical rods 5 of suitable diameter to en-sure rigidity are mounted in and secured by set screws to deep bosses 6 formed yon the wings 3. A bracket l is supported yon the rods 5 by means of split bosses 8, through which the rods pass. The bosses may slide on the rods or may be clamped thereto by tightening clamping screws El. The bracket is provided with tail pieces It terminating in internally screw-threaded =bosses II in which adjusting screws I2 engage.

In order to .adjust the height of the bracket l, the clamping screws 9 are slackened and the adjusting screws I2 4are turned to move the bracket upwards or downwards to the desired posi-tion, whereupon the clamping screws are again tightened.

Each front face I3 0f the bracket 'I is machined to a flat, and a part-cylindrical steel slide bar I 4 having a flat ground along its whole length is secured to each face I3 with the flat on the bar I4 presented to the fiat on the iace I3. The bars lare secured to the bracket by means of a number of bolts I5 spaced along their length. The ram IB has two lateral -projections or gibs I'I in which corresponding part-cylindrical grooves are machined and two axially spaced detachable part-cylindrical bushes I8, I9, which are a sliding t over the slide bars I4, are provided in each groove.

As the reciprocal movement of the ram I6 is effected in the usual manner by the crank 20 mounted in the upper part of the frame I of the press and yoperated by means yof a coupling 22, and the ram I6 is not mounted in the frame, it will be -obvious that any deflection of the frame is not transferred to the ram.

I claim:

1. A press for cutting sheet metal comprising an upright C-sh'aped frame, a work table supported by the lower part of said frame, a plurality of upright pillars supported by the lower part 3 of said frame at points below said work table and extending above said work table, a bracket carried on said pillars above said work table, a plurality of upright part-cylindrical members rigidv ly secured to said bracket, and a ram having a plurality of grooves of part-circular cross-section formed therein, said grooves co-operating with and sliding on said part-cylindrical members to guide said ram for reciprocation.

2. A press for cutting sheet metal comprising an upright C-shaped frame, a work table supported by the lower part of said frame, a plurality of upright pillars supported by the lower part of said frame at points below said work table and extending above said work table, a height-adjustable bracket slidably mounted on said pillars, means for clamping said bracket to said pillars at any desired height above said work table, a plurality of upright part-cylindrical members rigidly secured to said bracket, and a ram having a plurality of grooves of part-cylindrical cross-section formed therein, said grooves co-operating with and sliding on said part-cylindrical members to guide said ram for reciprocation.

3. A press for cutting sheet metal comprising an upright C-shaped frame, a work table supported by the lower part of said frame, a plurality of upright pillars supported by the lower part of said frame at points below said work table and extending above said work table, a height-adjustable bracket slidably mounted on said pillars, tailpieces extending rearwardly from said bracket, adjusting screws engaging said tail-pieces for raising and lowering said bracket, means for clamping said bracket to said pillars at any desired height above said work table, a plurality of upright part-cylindrical members rigidly secured to said bracket, and a ram having a plurality of grooves of part-circular cross-section formed therein, said grooves co-operating with and sliding on -said part-cylindrical members to guide said ram for reciprocation.

4. A press for cutting sheet metal comprising an upright C-shaped frame, a work table supported by the lower part of said frame, a plurality of upright pillars supported by the lower part of said frame at points below said Work table and extending above said Work table, a height-adjustable bracket slidably mounted on said pillars, split bosses on said bracket for receiving said pillars, tail pieces extending rearwardly from said bracket, adjusting screws engaging said tailpieces for raising and lowering said bracket, means for clamping said split bosses to said pillars at any desired height above said work table, a plurality of upright part-cylindrical members rigidly secured to said bracket and a ram having a plurality of grooves of part-circular cross-section formed therein, said grooves co-oper-ating with and sliding on said part-cylindrical members to guide said ram for reciprocation.

5. A press for cutting sheet metal comprising an upright C-shaped frame, a work table supported by the lower part of said frame, a plurality of upright pillars supported by the lower part of said frame at points below said work table yand extending above said work table, a bracket rigidly secured to said pillars above said work table, a plurality of upright part-cylindrical members rigidly secured to said bracket, a ram having a plurality of grooves of part-circular cross-section formed therein, and bushes of part-circular cross-section detachably mounted in said grooves, said bushed grooves cao-operating with and sliding on said part-cylindrical members to guide said ram for reciprocation.

CHARLES JOSEPH RHODES.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS 0 Number Name Date 2,051,447 Johansen et al Aug. 18, 1936 2,371,315 Rhodes Mar. 13, 1945 Re. 22,743 Sines Apr. 9, 1946 

